U.S. patent number 6,637,906 [Application Number 09/951,875] was granted by the patent office on 2003-10-28 for electroluminescent flexible film for product packaging.
This patent grant is currently assigned to Recot, Inc.. Invention is credited to Anthony Robert Knoerzer, Garrett William Kohl.
United States Patent |
6,637,906 |
Knoerzer , et al. |
October 28, 2003 |
Electroluminescent flexible film for product packaging
Abstract
A flexible electroluminescent film, and packaging material and
packages made therefrom, that incorporates electroluminescent
material within the polymer packaging film layers to enable the
film to be illuminated without an external light source. The film
may also comprise various thin-film items, such as power source,
inverter, switch, integrated circuit, radio receiver, and speaker,
all within the film layers. The film can be used in existing form
and fill packaging machines without substantial modifications to
the machines.
Inventors: |
Knoerzer; Anthony Robert
(Plano, TX), Kohl; Garrett William (Allen, TX) |
Assignee: |
Recot, Inc. (Pleasanton,
CA)
|
Family
ID: |
25492262 |
Appl.
No.: |
09/951,875 |
Filed: |
September 11, 2001 |
Current U.S.
Class: |
362/84;
362/156 |
Current CPC
Class: |
B65D
33/004 (20130101); B65D 75/545 (20130101); H05B
33/10 (20130101); H05B 33/12 (20130101) |
Current International
Class: |
H05B
33/10 (20060101); H05B 33/12 (20060101); F21V
033/00 () |
Field of
Search: |
;362/154,155,156,267,84,310 ;313/506,511 ;428/68,690,917 |
References Cited
[Referenced By]
U.S. Patent Documents
Other References
Technology Watch article entitled, "Little Future in Electronics,"
Popular Mechanics, Jan. 2001, p. 22. (1 page). .
SEIKO Precision article entitled "Electro Luminescence" found on
Jan. 30, 2001 at http://www.seiko-precision.com/html/el_co.htm (4
pages). .
Amcon International article entitled "LUXLED electro luminescence
technique" found at http://www.amcon-luxled.com/luxled/technic
1.htm, Dec. 31, 2000. (9 pages). .
World Producers, Inc. Light Emitting Diodes article entitled "A
growing number of applications" found on Jan. 30, 2001 at
http://www.worldproducts.com/home/wpi/ppg/ell/ell02t.htm. (10
pages). .
Power Paper Ltd. article entitled "MK3B Power Paper Cell" found at
http://www.powerpaper.com/techDataText2.html, Jun. 2000. (1 page).
.
Drawing of Electrode found at
http://www.powerpaper.com/batteryStructureText.html, Jun. 2000. (1
page). .
Flexible Circuit Technologies, Inc. article entitled "Membrane
Switches & Graphic Overlays" found on Jun. 21, 2001 at
http://www.flexetech.com/membrane.htm. (2 pages). .
Home Page for Memtronik Innovations, including article on Membrane
Switches, found at http://www.memtronik.com/start1.htm, Apr. 28,
1998. (8 pages). .
Metromark, Inc. article entitled "Membrane Switches and Graphic
Overlays That Perform as Well as They Look" found at
http://www.metromark.com/membrane.htm, 1998. (1 page). .
Home Page for Memtronik Innovations, including article entitled
"Electroluminescents" found at http://www.memtronik.com/start1.htm,
Oct. 6, 1998. (6 pages). .
Oak Ridge National Laboratory article entitled "Thin Film
Rechargeable Lithium Battery" found at
http://www.ornl.gov/ORNLTech/battery.html, Feb. 1994. (2 pages);
Jan. 2001 Popular Science Article entitled "Paper Thin Power" (1
page). .
Jan. 2001 Popular Science Article entitled "Paper Thin Power" (1
page)..
|
Primary Examiner: Sember; Thomas M.
Attorney, Agent or Firm: Cahoon; Colin P. Carstens, Yee
& Cahoon, L.L.P.
Claims
We claim:
1. A flexible film sheet comprising: a first polymer film layer; a
first electrode film layer bound to said first polymer film layer;
an electroluminescent material layer bound to said first electrode
film layer; a second electrode film layer bound to said
electroluminescent material layer; a second polymer film layer
bound to said second electrode layer; a power source electrically
connected to said electroluminescent material; and wherein said
flexible film sheet is suitable for use in a vertical form, fill,
and seal packaging machine, and the power source further comprises
a thin-film DC power source.
2. The flexible film sheet of claim 1 wherein the power source
further comprises a thin-film current inverter electrically
connected to the DC power source and the electroluminescent
material layer.
3. The flexible film sheet of claim 2 wherein the film further
comprises a circuit, said circuit located between said first
polymer layer and said second polymer layer, for conducting a
current from the DC power source, through the inverter, to the
electroluminescent material, and back to the DC power source.
4. The flexible film sheet of claim 1 wherein the flexible film
further comprises a thin-film switch electrically connected to said
DC power source and located between said first polymer layer and
said second polymer layer.
5. The flexible film sheet of claim 1 wherein the flexible film
further comprises an integrated circuit electrically connected to
said DC power source and located within said film layers.
6. The flexible film sheet of claim 1 wherein the flexible film
further comprises a thin-film radio receiver electrically connected
to said DC power source and located between said first polymer
layer and said second polymer layer.
7. The flexible film sheet of claim 1 further comprising a
thin-film speaker electrically connected to said DC power source
and located between said first polymer layer and said second
polymer layer.
8. A flexible package for containing a product, said package
comprising: a first polymer layer; a second polymer layer; an
electroluminescent thin film sandwiched between said first polymer
layer and said second polymer layer; a power source electrically
connected to said electroluminescent thin film; wherein said first
polymer layer, second polymer layer, and electroluminescent film
are bound together and arranged to form said flexible package.
9. The flexible package of claim 8 wherein the power source
comprises a thin-film DC power source electrically connected to an
inverter.
10. The flexible package of claim 8 further comprising a switch
electrically connected to said power source, whereby such switch
controls the input of power into the electroluminescent film.
11. The flexible package of claim 8 wherein said package comprises
a bag for containing a snack food product.
12. The flexible package of claim 8 further comprising an
integrated circuit electrically connected to the power source.
13. The flexible package of claim 8 further comprising a radio
receiver electrically connected to the power source.
14. The flexible package of claim 8 further comprising a speaker
electrically connected to the power source.
15. A method for producing a flexible package, said package
comprising two polymer film layers, said method comprising the
steps of: a) placing between the two polymer film layers an
electroluminescent film and a thin film power supply, wherein said
electroluminescent film and power supply are electrically
connected; b) sealing the two polymer film layers together, thereby
encasing the electroluminescent film and power supply within the
two layers and forming a sheet of thin-film, flexible material; c)
feeding said sheet of thin-film, flexible material into a form,
fill, and seal machine; and d) forming a package from said sheet of
thin-film, flexible material.
16. The method for producing a flexible package of claim 15 wherein
step d) further comprises forming a snack food product package.
17. The method for producing a flexible package of claim 15 wherein
step a) further comprises placing between the two polymer film
layers an integrated circuit electrically connected to the
electroluminescent film and power supply.
18. The method for producing a flexible package of claim 15 wherein
step a) further comprises placing between the two polymer film
layers a thin-film switch electrically connected to the
electroluminescent film and power supply.
19. The method for producing a flexible package of claim 15 wherein
step a) further comprises placing between the two polymer film
layers a thin-film radio receiver electrically connected to the
electroluminescent film and power supply.
20. The method for producing a flexible package of claim 15 wherein
step a) further comprises placing between the two polymer film
layers a thin-film speaker electrically connected to the
electroluminescent film and power supply.
Description
BACKGROUND
1. Technical Field
The present invention relates to electroluminescent flexible films
incorporated into food or other product packaging. This invention
allows product packaging to be illuminated without substantially
increasing film thickness or substantially decreasing the film
flexibility necessary to conform to varying product shapes. More
specifically, this invention can be used with existing
product-packaging equipment, such as a vertical form, fill, and
seal machine, to incorporate electroluminescent displays into
product packaging. More generally, this invention can be used in
any product requiring illuminated thin films or illuminated images
on thin films.
2. Description of Related Art
There are several examples of embodiments of illuminations on
various containers in the prior art. Such designs allow for
increased visibility of a design imprinted on the container in dark
conditions. Further, illuminated containers are more likely to grab
the viewer's attention than non-illuminated containers.
Illuminating decorative designs helps emphasize illuminated parts,
much like underlining helps emphasize marked text.
Prior art devices typically utilize bulky light sources for
illumination. For example, U.S. Pat. No. 5,567,054 uses a
chemiluminescent "wand" disposed within a pouch at the base of a
bag. The wand consists of two concentric tubes filled with two
different chemicals that produce light when mixed. This wand
illuminates the bag when the inner, frangible tube is broken to
allow the two chemicals to interact. However, the bag requires an
additional pouch to contain the wand. The manufacturing process for
making the bag would thus require additional manufacturing steps
for forming the pouch, placing the wand into the pouch, and
heat-sealing the pouch.
A handbag with a removable electroluminescent lamp was disclosed in
U.S. Pat. Nos. 5,067,063 and 5,268,827. Electroluminescent
technology is discussed in further detail below in reference to
U.S. Pat. No. 5,676,451. The electroluminescent lamp used in that
invention can illuminate both inside and outside the bag. The lamp,
however, must be manually attached to the inside wall of the bag by
some mechanical means, such as Velcro or clips. To mass-produce the
handbags, additional labor steps would be required to attach the
lamp to the inside wall. Alternatively, a separate machine would be
needed to make the attachment. Furthermore, the bag requires a
separate compartment to contain the battery and DC-to-AC converter.
The attachment of an electroluminescent lamp and the addition of
the batteries, a converter, a switch, the wiring, and containers to
house those materials would unnecessarily decrease the amount of
space available inside the bag.
Similarly, U.S. Pat. No. 4,926,296 discloses an illuminated
carrying bag with a light bulb attached to a sidewall. Batteries
contained in a pouch secured to that sidewall energize the light
bulb. Like the invention disclosed in the '063 and '827 patents,
the illuminating device in the '296 patent is bulky and requires
extra labor and/or equipment to incorporate into existing bags.
In another prior art reference, U.S. Pat. No. 5,676,451, a fabric
bag is illuminated with a flexible electroluminescent film strip
attached to the exterior of the bag. Electroluminescence is a light
emission phenomena resulting from the application of an electric
field to prepared phosphor powders sandwiched between sheet-metal
electrodes. Electroluminescent strips function with alternating
current (AC). Voltage is applied between the front and the back
electrode by way of an AC power source and the phosphor particles
are excited by the electric field, thereby producing a luminescent
energy. The film strip disclosed in the '451 Patent is energized by
a battery and inverter (DC-to-AC converter), both of which are
contained in a pouch. Although the electroluminescent film strip is
flexible in the preferred embodiment of the '451 patent and can
conform to the changing shape of the bag walls, the
electroluminescent film strip still is not part of the wall itself;
it still must be mechanically attached. Furthermore, the power
source requires its own pouch.
Prior to the current invention, no other invention incorporated
electroluminescent materials into self-contained, flexible
packaging films for use with product packaged in flexible film
packages, such as snack food packaged using a vertical form, fill,
and seal machine. Consequently, a need exists for flexible
electroluminescent films suitable for use with existing
film-packaging equipment or other uses requiring flexible
electroluminescent films, such as packaging for chips and other
snack food products. Such films should be easily manufactured and
readily adaptable to existing form and fill machines. Further, such
invention should save space and reduce the necessary amount of raw
materials by eliminating the need to attach a separate, exterior
light source to the packaging film.
Prior art methods utilized attached light sources that were prone
to detachment from shifting container contents or rough handling.
Consequently, a need exists for a light source for containers that
is not prone to detachment. By incorporating the light source
within the packaging film instead of merely attaching it onto the
film, such invention would prevent the light source from being
knocked loose during shipping or handling. The invention should
also be flexible in order to withstand the deformation of
containers that occurs during normal shipping and handling.
SUMMARY OF THE INVENTION
The proposed invention comprises a flexible electroluminescent
film, and packaging derived therefrom, in combination with other
elements capable of illuminating graphic designs contained within
the film layers. The invention can be used as flexible packaging
material and can be used in traditional packaging devices. All the
necessary components for illumination are incorporated within a
thin film sheet.
In one embodiment of the invention, the flexible electroluminescent
film is incorporated within the layers of a bag used to hold chips
or other snack food products. Electroluminescent material is
sandwiched within various polymer, ink, and moisture-absorbing
layers. A thin-film DC power source, a thin-film current inverter,
and a thin-film touch-sensitive switch ("power system") are all
incorporated within the layers of the packaging material. Thus, a
single sheet of film incorporating all these features can be fed
into a vertical form, fill, and seal machine. The
electroluminescent material, various ink layers, and opaque mask
layers are arranged in such a manner as to illuminate a graphics
image on the formed bag when the power system is activated.
The invention is a great improvement over the prior art for a
number of reasons. Incorporating the light source into the
enclosure material itself instead of attaching a separate light
source saves interior space and leaves more room for product to be
enclosed. Having the packaging and light source all in one piece
also avoids the problem of having attachments that can be knocked
loose during shipping or handling. It also avoids the problem of
enclosed items snagging or catching onto the light and/or the power
system.
Importantly, having the light source and power system already
incorporated into a film sheet saves time and expense for packaging
facilities. Whereas prior art solutions required extra machinery
and/or labor to attach electroluminescent lamps, no such additions
are necessary with this invention. The sheet comprising the
flexible electroluminescent film can be assembled on a film
converter and used in existing form, filling, and sealing packaging
systems for existing product lines.
Incorporating the electroluminescent layers into the packaging
layers saves raw material costs by preventing the duplication of
materials. In prior art systems involving electroluminescent lamps
separately attached to packaging walls, both the lamp and the
packaging walls required their own moisture-trapping layers.
Because the electroluminescent layers are within the packaging
layers, only one set of moisture-trapping layers is necessary.
The above as well as additional features and advantages of the
present invention will become apparent in the following written
detailed description.
BRIEF DESCRIPTION OF THE DRAWINGS
The novel features believed characteristic of the invention are set
forth in the appended claims. The invention itself, however, as
well as a preferred mode of use, further objectives and advantages
thereof, will be best understood by reference to the following
detailed description of illustrative embodiments when read in
conjunction with the accompanying drawings, wherein:
FIG. 1 is a schematic view of flexible electroluminescent film
components in one embodiment of the invention;
FIGS. 2a and 2b are perspective views of the flexible
electroluminescent film of one embodiment of the present invention
incorporated into a snack food bag;
FIG. 3 is a cross-section view of a prior art flexible
electroluminescent film incorporated in one embodiment of the
present invention;
FIG. 4 is a perspective view of the flexible electroluminescent
film of one embodiment of the present invention incorporated into a
snack food bag showing several components attached to the packaging
walls;
FIG. 5a is a perspective view of a display shelf with several snack
food bags that incorporate one embodiment of the flexible
electroluminescent film of the present invention arranged in a
collage presentation;
FIG. 5b is a perspective view of one of the bags in FIG. 5a with a
section of the first few layers of the film removed, along the line
(5b--5b) indicated on FIG. 5a, to show various components; and
FIG. 6 is a schematic view of the flexible electroluminescent film
of one embodiment of the present invention with an integrated chip
and speaker included.
DETAILED DESCRIPTION
FIG. 1 illustrates a schematic view of one preferred embodiment of
the flexible film sheet 10 incorporating the electroluminescent
features of the present invention. This figure highlights important
features of the sheet 10, including: an electroluminescent graphic
design 11 incorporated into the film; a thin-film battery 12, a
thin-film current inverter 13, a thin-film touch-sensitive switch
14, and other printed circuitry 15, all of which are incorporated
within the film layers. When the user touches the switch 14,
current flows from the battery 12 to the current inverter 13 where
the DC current is converted into AC. Then the current continues
through the closed switch 14 and to electrodes 16 that lead into
the electroluminescent layer. Once the electric current reaches the
electroluminescent layer, the layer energizes and the image 11
illuminates. The current then returns to the battery 12.
The components of the flexible film sheet 10 in FIG. 1 are not
limited to the physical locations displayed in FIG. 1. For example,
the power system, which includes the battery 12, switch 14, and
inverter 13, might be located far away from the image 11, with
circuitry 15 connecting the image 11 to the more distant power
system. Also, the components may or may not be visible to the user.
Certain areas of the film sheet 10 may contain opaque layers that
hide various components from sight. There may, for example, be an
ink layer covering the battery 12 and inverter 13 so that the user
only sees the switch 14 and the image 11. Color variations on the
image 11 can be accomplished by covering areas of the image with
different colored layers or by incorporating electroluminescent
film giving off different colors.
In addition, not all of the components may be necessary;
alternatively, additional or different components may also be
incorporated. For example, if the image 11 is to be illuminated
continuously for as long as the battery 12 lasts, then a switch 14
will not be necessary. If more current or more voltage is needed,
several batteries 12 might be incorporated into the film 10 in
series or in parallel. It is also possible to have several
electroluminescent images within the same piece of flexible film
sheet 10. All that would be required is that the printed circuitry
15 be arranged in such a way as to supply all images with current.
Other components, such as an integrated circuit 91 as shown in FIG.
5b, might be incorporated into the film sheet 10 in order to
control the manner of illumination. An integrated circuit 91, for
instance, might control which of several different images or
portions of a single image illuminate and also control when they
illuminate in order to create an interesting visual effect.
FIGS. 2a and 2b depict the flexible film sheet 10 with
electroluminescent features incorporated into the packaging of a
snack food bag. Corresponding reference numerals are used to
represent corresponding elements unless indicated otherwise. Only
the electroluminescent image 11 is visible in FIG. 2a, whereas all
the power components, such as the battery 12, inverter 13, switch
14, and circuitry 15, are visible in FIG. 2b. In FIG. 2a, opaque
ink layers within the film layers cover the layers containing the
battery 12, inverter 13, switch 14, and circuitry 15. The polymer
layers covering the electroluminescent material layer and power
component layers may contain portions that are opaque while other
portions are transparent. Thus, one can selectively choose which
portions of the various components are to be visible and which ones
are to be hidden.
The electroluminescent image 11 does not have to be confined to the
area as shown in FIGS. 2a and 2b. Several images may be spread
throughout the bag or packaging 31; each image may be powered by
its own power components, or by a common power source. One suitable
power source is the MK3B Power Paper Cell, manufactured by Power
Paper of Kibutz Einat, Israel. The power components also do not
have to be confined to the area as shown in the figures. For
instance, the portion of the packaging film 31 containing the
battery 12 might be located near the top or bottom of the bag, or
even within the seams 32 of the bag. The portions of the film
containing the circuitry 15 might be located near the perimeter of
the bag in order to make the components more visibly appealing. In
addition, the essential elements for illumination, namely the front
and rear electrode layers 52, 55 and the electroluminescent
material layer 53, as shown in FIG. 3, do not have to be present
throughout the entire packaging film 31. Those elements are only
necessary in the illuminable portions of the film and do not have
to be present in non-illuminable portions. Companies such as
Memtronic of Montreal, Canada, and SEIKO Precision of the United
Kingdom, manufacture electroluminescent material suitable for use
with the layers comprising the instant invention.
Although the preferred embodiment of the invention is in a snack
food bag as shown in either FIG. 2a or FIG. 2b, the invention can
also be used in any application requiring flexible
electroluminescent films. For example, the invention might be used
for packaging pharmaceuticals, pet foods, liquids, and any other
number of products that can be marketed in a flexible package.
Further, such invention can be used for a number of other
point-of-sale applications and advertising applications, such as
billboards, posters, and displays, where the electroluminescent
film arrangement of the Applicants' invention can be substituted
for the paper or thin film presently used in such applications.
FIG. 3 depicts in further detail a prior art combination of various
layers comprising the flexible electroluminescent film 35 of one
embodiment of the invention. In this embodiment, the
electroluminescent film 35 is made of eight layers: an outer
sealing layer 50, an outer desiccant layer 51, a front electrode
52, electroluminescent material layer 53, insulation 54, rear
electrode 55, an inner desiccant layer 56, and inner sealing layer
57. The inner and outer sealing layers 50, 57 can be made of
polypropylene, polyethylene teraphthalate (PET) or other polymer
film materials typically used in the packaging industry. In one
embodiment of the invention, discrete pieces of the
electroluminescent material 35, each designed to present a discrete
image, are sandwiched between two layers of polymer material at
regulated intervals. This can be accomplished using a film
converter, thus building a single flexible sheet of polymer
material having the electroluminescent film 35 embedded therein.
Likewise, the power system used to illuminate the
electroluminescent film 35 can be electrically connected to the
electroluminescent film 35 and placed between the two polymer
layers such that all of the elements required to provide for
electroluminescence on a formed package are embedded between the
two polymer layers. The thus formed flexible film sheet can then be
fed into a form and fill machine, such as a vertical form, fill,
and seal machine, resulting in the formation of a package or bag
having the electroluminescent image feature.
Returning to FIG. 3, to produce colorful images, the outer sealing
layer 50 may contain color pigments, and different areas of the
layer 50 may be pigmented with different colors; alternatively,
some areas may be left clear. Because the inside layer 57 may
encounter a different environment than the outside layer 50, the
inner and outer sealing layers 50, 57 may also be of different
materials. For example, in the snack food bag embodiment displayed
in FIG. 2a, the outside sealing layer 50 can protect against dust,
dirt, moisture, and abrasion. Thus the outside layer 50 might be
15-40 microns. The inner layer 57, on the other hand, may come in
contact with salt and grease from the food product inside the bag
30, thus 15-50 microns might be more appropriate for the inner
layer 57. Any common film-packaging desiccant can be used for the
two desiccant layers 51, 56, such as talc, moisture absorbing
coatings such as PVOH, or moisture absorbing resins such as EVOH,
PET, or Nylon. Even the product itself can act as a desiccant,
thereby eliminating the need for desiccant layers 51, 56.
The front electrode 52 preferably is a transparent electrode such
as conductive polyester, but any relatively clear and conductive
film layer will suffice. This front electrode layer 52 may also be
tinted with color if so desired. The electroluminescent layer 53
preferably consists of phosphor particles that illuminate when
energized by electrical current. However, fluorescent pigments or
luminophores may also be used. The composition of the
electroluminescent layer 53 can be adjusted to produce different
colors upon illumination. Under the electroluminescent layer 53 is
an insulation layer 54 that preferably consists of a dielectric
material. However, the electroluminescent material may be dispersed
within the insulating dielectric material; therefore it is possible
for the electroluminescent layer 53 and the insulation layer 54 to
be combined into one layer. The rear electrode layer 55 preferably
consists of a reflective metallic layer such as silver. However,
the rear electrode 55 instead may be opaque, translucent, or clear.
For example, a carbon electrode layer may be used for the rear
electrode 55.
In a preferred embodiment, the electroluminescent film 35 must be
thin enough to use on a film converter and a standard vertical
form, fill, and seal machine with little adjustment. The thickness
of each layer relative to the other layers does not have to conform
to the relative thickness as shown in FIG. 3. In the embodiment
illustrated, the thickness of each layer would be as follows: outer
sealing layer 50, between 15-40 microns; outer desiccant 51,
between 1-10 microns; front electrode 52, between 1-5 microns;
electroluminescent material 53, 3-15 microns; insulation 54,
between 1-5 microns; rear electrode 55, between 1-5 microns; inner
desiccant 56, between 1-10 microns; and inner sealing layer 57,
between 15-50 microns. However, the thickness of each layer may
vary beyond these prescribed ranges depending on the properties
desired and the materials used.
The polymer film layers that enclose the electroluminescent film 35
can, for example, comprise oriented polypropylene as an outside
layer and PET as an inside, or product side, layer. Each polymer
film layer can, in fact, comprise more than one discrete film layer
laminated to one or more additional film layers, as is well known
in the art. The outer polymer film layer will typically incorporate
an ink layer or other pigmentation to enhance the graphic
presentation. The selection of the polymer film material layers is
not limited to that disclosed specifically herein but, rather, is
driven by the selection of thin-film material with the appropriate
combined barrier properties and graphics presentation capabilities
for the particular application desired. In addition, those skilled
in the art understand that a different combination of layers and
layer dimensions may be used to create thin electroluminescent
films. The resulting film must still be thin enough and flexible
enough, when combined with polymer film layers, to form a single
flexible film sheet to be used in conventional packaging machines,
such as the Universal Bag Maker form, fill, and seal machine by
Woodman.
The preferred embodiment of the invention thereby incorporates all
of the individual components required to provide
electroluminescence on a package within a single sheet of flexible
film. As noted previously, the invention can be constructed using
conventional film converters. Therefore, a sheet of flexible film
incorporating all of the previously described features can be
provided in rolls adaptable for use on vertical form, fill, and
seal machines. The sheet is fed into the form and fill machine and
then sealed into a tube, sealed at one end, filled, sealed at the
other end, and cut, all as is well known in the art. The end result
is a flexible film package, such as the common potato chip bag,
incorporating all of the individual elements, such as the battery,
inverter, switch, and electroluminescent material, within the
packaging film. The elements necessary for the electroluminescent
feature need be located only in portions of the film, therefore not
increasing the thickness of the film at critical seal areas.
Consequently, with certain embodiments of the invention, no
adjustment of pressure or dwell times is needed at the seal jaws or
other sealing surfaces of a form and fill machine using the
flexible film of the present invention for applications with
existing product lines.
FIG. 4 depicts an embodiment of a snack food package wherein the
power components are not thin-film components sandwiched within the
packaging film but, instead, are located elsewhere. For example,
FIG. 4 shows in phantom a button-type battery 71, a solid-state
inverter 72, and electrical wires 73 located inside a snack product
bag and attached to one of the bag walls. The electrical wires 73
connect both battery 71 and inverter 72 to the electroluminescent
image 11 via connecting electrodes 74. The connecting electrodes 74
run from outside the film 31, through the various film layers shown
in FIG. 3, and to the front and rear electrode layers 52, 55 of
FIG. 3 in order to connect the outside power source 71, 72, 73 to
the electroluminescent image 11 within the packaging film layers
31. While FIG. 4 shows the battery 71, inverter 72 and wires 73
attached to the inside wall of the snack product bag, those
components may alternatively be attached to the outside of the bag
or sandwiched between polymer layers.
FIG. 5a depicts an illuminated collage effect that is possible
across a display of snack product bags 30 incorporating flexible
electroluminescent features 60. No single bag displays the complete
image, but the complete image appears over many bags 30
collectively arranged. There are several methods for accomplishing
this collage effect. In one embodiment, each bag 30 in the collage
has a fixed and predetermined image displayed on the flexible
electroluminescent features 60. The image on any given bag may be
different from the image on another bag. When arranged in a
particular fashion, each bag 30 contributes to an overall image,
much like each piece of a jigsaw puzzle contributes its partial
image to form a larger picture. In another embodiment, each bag 30
has several different image layers that can be illuminated. The
location of each bag 30 within the collage display would determine
which image is displayed. Each image layer would consist of a front
electrode layer, an electroluminescent layer, an insulation layer,
a rear electrode layer, and another insulation layer, all
sandwiched within the inner and outer package film layers. In order
for the illuminated image layer to be visible through the
non-illuminated image layers, all image layers except for the
inner-most layer should use transparent electrode layers. The
individual bags 30 can also be programmed to illuminate in
sequence, thus creating a rolling effect or other animated
presentation for the entire collage.
FIG. 5b depicts a close up view of one of the chip bags 30 within
the collage with the outer film layers cut away along a line
(5b--5b) as shown in FIG. 5a. As shown in FIG. 5b, an integrated
circuit 91 can be sandwiched within the packaging sheet to control
which image layer is illuminated. If the collage display appears in
a supermarket isle, for example, a nearby radio control device can
transmit radio signals to the radio receivers 92, which are
incorporated into the film layers. Although FIG. 5b depicts a
remote-control system using a radio receiver 92 and integrated chip
91, other forms and methods of controlling which images are
illuminated are also possible. Those skilled in the art know
equivalent means for selectively energizing different circuits,
which in turn illuminate different images within the flexible
packaging layers.
There are limitless uses for flexible electroluminescent films in
packages. FIG. 6 depicts an embodiment incorporating a thin speaker
111 and integrated circuit 91 within the film layers in addition to
the features shown in FIG. 1. Both the image 11 and the speaker 111
may be switched on and off by one or more switches 14, such as
membrane switches made by Memtronic of Montreal, Canada, or
membrane switches made by Flexible Circuit Technologies of Saint
Paul, Minn. Alternatively, an oxygen sensor might take the place of
one or more switches 14, and the circuitry 15, 91 could be designed
to either turn off or turn on the image 11 and/or speaker 111 if
the sensor senses a certain level of oxygen within the bag. When
such an oxygen sensor is incorporated into a snack bag 30 like the
ones depicted in FIGS. 4-5b, the flexible electroluminescent film
10 itself acts as a freshness-assessing device. Additional switches
14 can be used in combination with specialized circuitry 15, 91 in
order to provide a simple video game on the surface of a package.
Such circuitry 15, 91 can also be designed for use with a coupon or
game promotion, whereby the consumer energizes the
electroluminescent image 11 in order to indicate what prize or
coupon has been won.
While the invention has been particularly shown and described with
reference to a preferred embodiment, it will be understood by those
skilled in the art that various changes in form and detail may be
made therein without departing from the spirit and scope of the
invention.
* * * * *
References